1. Field Of The Invention
The invention pertains to a method for producing a driving or conveyor belt made of rubber or rubberlike material, having a reinforcing member consisting of one or more layers or textile fabric comprising warp and woof threads of a synthetic material, selected from the group comprising polyester, polyamide and/or aramid or a combination thereof.
2. Description Of The Related Art
To achieve increased strength known prior art driving or conveyor belts employ two or more reinforcing members to achieve a degree of belt strength up to a maximum of 1.600 N/mm width. The value of 1.250 N/mm per width should preferably not be exceeded in such belts. To each a higher degree of strength the number of reinforcing members have to be increased, thus leading to a further increase in thickness of the belt which requires an undesirably large driving and/or guide rollers.
Additional known belts have a single reinforcing member that, in order to reach the required degree of strength, has a thickness of several millimeters. Such belts also require the imbedding of the reinforcing member in the synthetic material or rubber or rubberlike material, to accomplish the necessary binding of warp and woof threads for a lasting durability, the desired low elasticity as well as a satisfactory resistance against tearing out of connecting claws. This requires the complete saturation of the reinforcing member with synthetic material or rubber or rubberlike material. The necessary saturating of the reinforcing member, that is required for such a belt, however, can only be achieved with synthetic compositions, for instance polyvinyl chloride, considering the bulkiness of the reinforcing member. As compared to rubber or rubberlike material synthetic materials glide relatively easily on the driving or guide rollers and show an increased degree of wear, the cover layers of high quality belts should as usual be composed of rubber or rubberlike material. The binding process of the cover layers of rubber or rubberlike material to the synthetic material for instance polyvinyl chloride, of the embedding layer of the reinforcing member, however, is very expensive and complicated. It e.g. presupposes the use of natural fibers in the warp and woof elements of the reinforcing member. The use of natural fibers, however, conceals the troublesome disadvantages of absorption of moisture, the process of rotting and weakening binding. The binding in the contact surfaces between the synthetic material of the reinforcing member and rubber or rubberlike material of the cover layers is particularly susceptible.
The use of a reinforcing member of sufficient strength and thickness, which is made exclusively of synthetic threads, such as polyester, polyamide and/or aramid threads and combinations thereof, which is embedded in a rubber or rubberlike material has not been possible to date as the rubber solution will not penetrate the reinforcing member, which nevertheless would be a necessity to achieve the requisite durability, low elasticity as well as resistance to the tearing out of connecting claws.